Final answer:
The main source of hydrogen for hydrogen-powered vehicles is hydrogen fuel cells. These cells, which have been used in vehicles such as the Toyota Fuel Cell Hybrid Vehicle, are promising but still expensive and energetically inefficient. Widespread adoption is currently limited by high production costs and infrastructural challenges.
Step-by-step explanation:
The main source of hydrogen for hydrogen-powered vehicles at present is through a technology called hydrogen fuel cells. These fuel cells generate electricity by combining hydrogen and oxygen in a catalytic process, with water as the only byproduct. Such cells have powered a range of vehicles, from satellites and space capsules to cars and buses.
One of the most notable hydrogen-powered vehicles is the Toyota Fuel Cell Hybrid Vehicle (FCHV), which has a fuel cell that generates electricity from hydrogen and oxygen. However, despite its promise, this technology is still in an experimental phase and is relatively costly. The 2008 Honda FCX Clarity was an early production car using a fuel cell, highlighting the technology's potential despite current limitations like high costs and the energy inefficiency of hydrogen production.
Overall, while hydrogen fuel cells offer a potentially cleaner alternative to traditional combustion engines, their widespread adoption is currently hindered by factors such as the high cost of production, the requirement for large quantities of elemental hydrogen, and the significant energy loss in hydrogen production.